eta application delayed for visa exempt national

[jigsawe]

Hi,

I am from a visa exempt country, and I am planning to visit Canada in about a month. I applied for an eta, but I got a message saying my application will take longer than expected. I previously have a record of being denied entry to Canada, and was not allowed to re-enter for a year, due to not having proper work authorization (the one year period has well passed)

I read in other posts that some eta applications might take up to a month.

I am planning to visit the US, then to Canada.

Would it be a problem if I went to the US, and went to Canada by land? If I did, would I need an eta to fly back from Canada to US for my return flight?

Thanks in advance.